A reader asked if it was possible to use an exterior door in the house interior:
I have an interior door in a brand new house and would like to replace it with an exterior door. Can I use existing frame and purchase an exterior door? Also, what other items do I need to do? Insulation, weather strip at bottom, etc.? If the exterior door is wider than the interior door, can it be trimmed or does that depend on the composition of the door?
Yes, you can use an exterior door on the interior. Other than replacing a flimsy hollow core door with a better soundproofed solid door, there are not many practical reasons why you might want to do this.
If you're thinking of this as an "easy way" or "cheap way," then you may need to think of a number of things.
- Inward Swing: One thing to keep in mind is that exterior doors open inward. Your hinges may be incised into the door frame, though it is possible to reverse them.
- Interior vs. Exterior Door Sizing: Exterior doors typically run 36" wide, whereas interior doors are not as wide (30"). Cutting will be required.
- Hanging a Slab Door vs. a Pre-Hung Door: Pre-hung doors come complete. The door is already hung by hinges to the door frame. Though these are heavy to move and require skillful carpentry, they result in a door that swings perfectly. For novices, slab doors are touchy to hang and the swing doesn't always turn out so well.
- Composition: Many exterior doors are metal-clad wood or fiberglass, which would leave you a ragged edge on the cut side. Even wood doors are not solid slabs of wood, as they are composed of various pieces called rails, stiles, panels, and mullions. If you cut too far, the door loses its stability and may fall apart.
- Loss of Symmetry: If the door has a paneled appearance, the panels will no longer be symmetrical if you trim off one end. You would either have to trim off both ends to create symmetry or accept a slight loss of symmetry if you cut just one side.
- Precise Cutting Required on a Table Saw: Precise cutting is needed. You can't make a straight cut with a hand saw. Even with a table saw, it will be difficult to make a perfect cut. You would have to have a professional-size table saw that could accommodate the entire door.
- Weathering: Exterior doors are meant to be rained on, snowed on, battered, and subjected to relentless UV rays from the sun. This means that your intended door might be warped or buckled from this abuse, making it difficult to install in your interior application.